Bruno Bonello's "Saint Laurent" features a fair amount of laying around with its s|Sony Pictures Classics

The story director Bertrand Bonello has been hawking is that when he heard someone else was making an Yves Saint Laurent biopic — last year’s more traditioanl “Yves Saint Laurent” — he chucked out the first 20 or 30 pages of the script to his one, called simply "Saint Laurent." Thing is, it’s hard to imagine his film ever being close to normal. It’s a film in love not only with not being a Wikipedia movie (like “Yves Saint Laurent” — sorry this is confusing), but with not even giving you basic facts. It opens in media res, with its version of YSL (Gaspard Ulliel, with a big, sloppy smirk plastered on his face) already a fashion god. The nature of key relationships — including with manager/life partner Pierre Berge (Jeremie Renier) and muse Loulou de la Falaise (Lea Seydoux) — remains mysterious, both characters popping in and out of the narrative and sometimes just hanging in the background. It covers nearly a decade and mostly in linear fashion, but the scenes chosen often feel selected at random and don’t always parse as a continuous, focused story.

These are all pros, not demerits, of course, and once one adjusts to the apparent chaos “Saint Laurent” is a movie to get lost in — an old school epic of excess that recalls the stubbornly meandering cinema of Luchino Visconti. To make things slightly easier on the audience, Bonello has chosen to focus on the most movie- and tabloid-friendly chunk of his life: the span from 1967 to 1976, when he was at the bottom of a drug and drink hole, emerging periodically to create the best, most iconoclastic work of his life. The middle section bros down with Saint Laurent and a key play pal: rich party kid Jacques de Bacher (a de-floppy-haired Louis Garrel. They stumble about orgies, lounge about, sleep passed out on floors and share drugs via tongues. (Also unlike “Yves Saint Laurent,” “Saint Laurent” — again, sorry — fully throws itself into sex.)

De Bascher was a minor character in “Yves Saint Laurent” — just a hissable predator who engineered its hero’s fall before his rise. “Saint Laurent” frontloads him, making him one of the great loves of his life. It’s indicative of the film’s overall coolness with debauchery, which goes beyond being merely non-judgmental. Where something like “Yves Saint Laurent” depicts these scenes as out-of-control and purgatorial, “Saint Laurent” presents them calmly and plainly, only raising its fist when a neglected cute dog starts lapping up spilled drugs. If Bonello’s film has any real focus it’s on the way self-destruction is, for those who do it, more comforting than dull reality. Bonello’s gets it — the fun of self-abuse and how it’s tied up in fear of the boring, perhaps creatively drab life that lies on the other side.

That makes “Saint Laurent” sound more focused than it is. Sometimes Bonello just lets scenes that have no clear tie to anything else play out. There’s a lengthy business meeting between Berge and American execs that exists to show Saint Laurent’s disconnection from that part of his empire, but also exists so that Bonello can play with how neither side speaks the language, forcing a poor but game interpreter to speak cacophonously underneath the entire scene. There are numerous party and club bouts, filled with numerous fits of obscure, highly Shazam-able R&B, from the likes of Patti Austin, Luther Ingram and The Metros. (Bonello himself composed the cool ’70s-style electronic music that backs the seedier stretches.) Like Assayas, Bonello loves the sound pop music has when it’s played in a public setting, and loves to watch bodies at play. Stand-outs include Lea Seydoux, too briefly frugging like a boss, and Aymeline Valade’s statuesque blonde bombshell Betty Catroux, who gets the film’s sole traditional biopic entrance, but a good one: dancing to nearly the entirety to CCR’s cover of “I Put a Spell on You.”

In these sequences, “Saint Laurent” casts itself adrift, getting lost to the music and in the moment, indifferent to what could be a tighter overall shape. It still has the traces of a biopic structure. It hilariously regulates about 20 seconds to a token lovers’ tiff between Saint Laurent and Berge, but it still obeys a general fall-and-rise structure, culminating in a comeback that at least has the decency to be a transcendent sensory overload. But it’s still open and shambling, soaking in the sights and sounds and feelings of watching the end times for a way of life. Bonello did much the same thing with his even better previous film, “House of Pleasures,” a melancholic hang with turn-of-the-(last)-century high-end prostitutes. “Saint Laurent” is more upbeat, giddily seizing on the hyper-decadence of an era that only lives on in memories and in movies like this. All this is to say that, unlike with the other YSL movie, you could never, ever watch this with your grandma.